Final answer:
The interest in employer-provided benefits from a social aspect relates to the social agenda, balancing social benefits and costs with no clear impact on economic growth demonstrated by unionization rates.
Step-by-step explanation:
The question seems to be concerned with the societal interests in employer-provided benefits and how this aligns with a broader social agenda. In some societies, the benefits of programs like employer-provided healthcare may outweigh the costs due to the resulting social benefits, which include both private benefits to the employees and external benefits to the society, such as better overall health outcomes and improved work productivity.
The social rate of return on such programs is high when the paybacks to society, such as a healthier workforce and reduced healthcare spending, are taken into account. In contrast, solidary benefits, such as joining a group because you care about a cause (option 'c'), serve to align individual benefits with social causes, thus fostering community and shared societal goals. From a social point of view, the benefits of unions and their costs often seem to counterbalance, with no clear evidence pointing to a significant impact on economic growth in relation to the proportion of unionized workers.